<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8"/>
    <title>Title</title>
</head>
<body>
<ul>
    <li id="l1" class="c1">北京</li>
    <li id="l2">上海</li>
    <li>广州</li>
    <li>深圳</li>
</ul>
<ul>
    <li>郑州</li>
    <li>西安</li>
</ul>
</body>
</html>